Hypophosphatasia in a newborn infant.

Infantile type hypophosphatasia, an autosomal recessive disease with severe clinical manifestations, is characterized biochemically by subnormal activities of circulating alkaline phosphatase. In this report, we presented a five-day-old male with this rare disorder. His parents were first cousins, and he was first seen for jaundice. He had soft calvaria, large fontanel, extremely wide cranial sutures, low-set ears, a depressed nasal bridge, funnel chest, and short and bowed distal limbs. Roentgenographic studies showed widened sutures and poor ossification of the skull, bowing of the femora and slight modeling defects in the long bones. A low serum alkaline phosphatase activity led us to measure excretion of phosphoethanolamine and found it to be increased.